1. Field of the Invention
The present invention relates to an image projecting system for projecting an image on microfilm onto an image receptor on a larger scale. More particularly, it is concerned with an image projecting system such as a reader or a reader printer, having a masking unit for shielding an image area other than a desired image area of a microfilm and allowing only the desired image area to be projected onto an image receptor.
2. Description of Related Art
A reader is used for projecting a desired image onto a screen out of images recorded on microfilm, and a reader printer has a screen for the projection thereon of any image out of images recorded on microfilm and a copying machine for printing that image. Where an image projecting system, e.g. a reader or a reader printer, is used in a bank, images of a large number of checks, etc. are recorded at a high contraction rate on a single microfilm and a desired image is projected onto the screen. If necessary, that image is projected onto a photosensitive medium to make a copy thereof. In such an image projecting system, it is necessary that only the required portion out of many images recorded on the microfilm be projected onto the screen and copied.
Japanese Utility Model Publication No. 18817/80 discloses a reader which has a masking plate for projecting a desired image portion onto a screen out of image recorded on a microfich film and for shielding the other unnecessary portion. In the presence of such masking plate, the masked portion is indicated as being illegible on the screen, or unmasked and masked portions are indicated discriminatively.
Japanese Patent Laid Open No. 110924/81 discloses a reader printer having two masking plates which are disposed in positions adjacent to a photosensitive drum so that they can move toward and away from each other. These masking plates, which are movable axially of the photosensitive drum, are each interlocked with an indication plate which indicates a portion corresponding to the copying area of a screen.
Japanese Patent Laid Open No. 242447/85 discloses a copying machine which has a sheet-like light shielding member capable of expanding and contracting in the longitudinal direction and a sheet-like light shielding member capable of expanding and contracting in the transverse direction, below an original-bearing table, for changing the copying region, whereby light from a lamp is directed to only the portion of an original according to the size thereof.
Japanese Utility Model Publication No. 104443/86 discloses a copying machine in which a sheet-like light shielding member formed with plural sizes of openings corresponding to the shapes of originals is provided below an original-bearing table, whereby an opening of a size matching the size of an original to be copied is positioned oppositely to the original and light is directed to the original through that portion.
Nevertheless, all of the above-mentioned techniques have the problem that the masking range cannot adjust arbitrarily.